Currently, investigations concerning the improvement of crop yield are mainly focused on the following aspects: 1. increasing crop sources, viz. improving crop photosynthesis; 2. elevating the sink volume; and, 3. enhancing the transport ability of photosynthate from source to sink. Among them, elevation in the sink volume and enhancement of transport ability of photosynthate from source to sink are effective breeding approaches.
Several approaches have been adopted to enhance crop yield and modify the crops. However, there still lacks effective means. With respect to rice, the major cereal crops of China, grain incomplete filling is present in many high yield varieties, especially in super hybrid rice and rice varieties with large ear and large grain, and greatly affects the improvement in the rice yield. In addition to rice, wheat and maize (Zea mays) have been grown worldwide as an important grain crops. Together, they constitute the world's major staple food crops. Grain incomplete filling also impacts wheat, maize, and other crops.
Therefore, it is desirable to search for an effective approach in the field to solve the problem of grain incomplete filling, thus further modifying the crops and enhancing the crop yield as well as crop quality.